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The %PHY-4-EXCESSIVE_ERRORS: Excessive FCS, data, or idle word errors found on interface [chars]error message is displayed in the logs of the Cisco Catalyst switch

Core issue

This error message is seen when the PHY errors (Idle error, Symbol error, and CRC error) increases the total threshold value of 2 in a 5 minutes period. A background process wakes up each 5 minutes to check if the PHY has idle error, receive error, or crc error in the last 5 minutes period.

The occurence of error message increases due to any of the following reasons

1. You disconnect and connect a cable

2. when the interface shutsdown

3. When the connected device reboots

4. When the speed setting is changed


Issue the show interface privileged EXEC command on the specified interface, and check for cyclic redundancy check (CRC) and other input errors. If errors are excessive, enter the shutdown interface configuration command and then the no shutdown interface configuration command to reset the interface.

Error message